在C＃中从Google驱动器文件获取元数据

Question

我正在尝试获取有关所有Google云端硬盘的元数据信息。 这是我的代码：

static void Main(string[] args)
    {
        Console.ForegroundColor = ConsoleColor.Green;
        var clientId = "MyID";
        var secret = "MySecret";
    var service = GoogleDriveFileListDirectoryStructure.AuthenticateOauth(clientId, secret, "AppliUserAutor2");

        var allFiles = GoogleDriveFileListDirectoryStructure.ListAll(service, new GoogleDriveFileListDirectoryStructure.FilesListOptionalParms { Q = "('root' in parents)", PageSize = 1000 });
        GoogleDriveFileListDirectoryStructure.PrettyPrint(service, allFiles, "");

        Console.ReadLine();
    }
internal class GoogleDriveFileListDirectoryStructure
        {                
            public static DriveService AuthenticateOauth(string clientId, string clientSecret, string userName)

        {
            try
            {
                if (string.IsNullOrEmpty(clientId))
                    throw new ArgumentNullException("clientId");
                if (string.IsNullOrEmpty(clientSecret))
                    throw new ArgumentNullException("clientSecret");
                if (string.IsNullOrEmpty(userName))
                    throw new ArgumentNullException("userName");

                // These are the scopes of permissions you need. It is best to request only what you need and not all of them
                string[] scopes = new string[] { DriveService.Scope.DriveReadonly };        //View the files in your Google Drive

                var credPath = System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal);
                credPath = System.IO.Path.Combine(credPath, ".credentials/apiName");

                // Requesting Authentication or loading previously stored authentication for userName
                var credential = GoogleWebAuthorizationBroker.AuthorizeAsync(new ClientSecrets { ClientId = clientId, ClientSecret = clientSecret }
                                                                                             , scopes
                                                                                            , userName
                                                                                             , System.Threading.CancellationToken.None
                                                                                             , new FileDataStore(credPath, true)).Result;
                // Returning the SheetsService
                return new DriveService(new BaseClientService.Initializer()
                {
                    HttpClientInitializer = credential,
                    ApplicationName = "Drive Oauth2 Authentication Sample"
                });
            }
            catch (Exception ex)
        {
            Console.WriteLine("Create Oauth2 account DriveService failed" + ex.Message);
            throw new Exception("CreateServiceAccountDriveFailed", ex);
        }
    }

    public class FilesListOptionalParms
    {
        /// The source of files to list.
        public string Corpus { get; set; }

        /// A comma-separated list of sort keys. Valid keys are 'createdTime', 'folder', 'modifiedByMeTime', 'modifiedTime', 'name', 'quotaBytesUsed', 'recency', 'sharedWithMeTime', 'starred', and 'viewedByMeTime'. Each key sorts ascending by default, but may be reversed with the 'desc' modifier. Example usage: ?orderBy=folder,modifiedTime desc,name. Please note that there is a current limitation for users with approximately one million files in which the requested sort order is ignored.
        public string OrderBy { get; set; }

        /// The maximum number of files to return per page.
        public int PageSize { get; set; }

        /// The token for continuing a previous list request on the next page. This should be set to the value of 'nextPageToken' from the previous response.
        public string PageToken { get; set; }

        /// A query for filtering the file results. See the "Search for Files" guide for supported syntax.
        public string Q { get; set; }

        /// A comma-separated list of spaces to query within the corpus. Supported values are 'drive', 'appDataFolder' and 'photos'.
        public string Spaces { get; set; }
    }
    public static Google.Apis.Drive.v3.Data.FileList ListAll(DriveService service, FilesListOptionalParms optional = null)
    {
        try
        {
            // Initial validation.
            if (service == null)
                throw new ArgumentNullException("service");

            // Building the initial request.
            var request = service.Files.List();

           request.PageSize = 100;

            //request.Fields = "nextPageToken, files(id,name,size,description,createdTime,webViewLink)";

            // Applying optional parameters to the request.
            request = (FilesResource.ListRequest)SampleHelpers.ApplyOptionalParms(request, optional);

            var pageStreamer = new Google.Apis.Requests.PageStreamer<Google.Apis.Drive.v3.Data.File, FilesResource.ListRequest, Google.Apis.Drive.v3.Data.FileList, string>(
                                               (req, token) => request.PageToken = token,
                                               response => response.NextPageToken,
                                               response => response.Files);

            var allFiles = new FileList();
            allFiles.Files = new List<File>();

            foreach (var result in pageStreamer.Fetch(request))
            {
                allFiles.Files.Add(result);
            }

            return allFiles;
        }
        catch (Exception Ex)
        {
            throw new Exception("Request Files.List failed.", Ex);
        }
    }

当我尝试通过此请求询问更多信息时：

request.Fields = "nextPageToken, files(id,name,size,description,createdTime,webViewLink)";

我只有29个结果（allFiles），其中包含所有需要的信息，但实际上我有1699个文件。 当我不指定任何字段请求时，我可以列出所有文件，但是我只有ID和名称文件。